Meningeal Lymphatic Endothelial Cells (MLECs) are specialized lymphatic vessel cells lining the meningeal lymphatic vessels in the dura mater. These cells represent a critical component of the brain's lymphatic system, enabling cerebrospinal fluid (CSF) drainage, immune cell trafficking, and waste clearance from the central nervous system (CNS).[1]
Meningeal lymphatic vessels were rediscovered in 2015 as functional lymphatic vessels running along the dural sinuses and meningeal arteries.[2] MLECs are:
MLECs exhibit characteristic lymphatic endothelial morphology:
| Marker | Expression | Function |
|---|---|---|
| Prox1 | High | Master regulator of lymphatic identity |
| Lyve1 | High | Hyaluronic acid receptor, cell adhesion |
| Podoplanin (PDPN) | High | Platelet aggregation regulation |
| Vegfr3 (Flt4) | High | VEGF-C receptor, lymphangiogenesis |
| CCL21 | Moderate | Chemokine for immune cell recruitment |
| Prox1 | High | Transcription factor for lymphatic fate |
MLECs form the primary drainage pathway for CSF:[3]
MLECs support CNS immune functions:
Critical for clearing:[4]
Meningeal lymphatic dysfunction contributes to AD pathogenesis:[5]
MLECs may influence PD progression:
| Disease | MLEC Relevance |
|---|---|
| MS | Autoimmune infiltration, drainage of myelin debris |
| FTLD | TDP-43 clearance pathways |
| ALS | Immune cell trafficking abnormalities |
| Traumatic Brain Injury | Post-injury waste clearance |
Potential therapeutic approaches:[6]
Louveau A, et al. Structural and functional features of central nervous system lymphatic vessels. Nature. 2015. ↩︎
Aspelund A, et al. A dural lymphatic vascular system that drains brain interstitial fluid into the cervical lymphatic nodes. J Exp Med. 2015. ↩︎
Iliff JJ, et al. A paravascular pathway facilitates CSF flow through the brain parenchyma and the clearance of interstitial solutes, including amyloid. Sci Transl Med. 2012. ↩︎
Bakker EN, et al. Lymphatic clearance of the brain: Perivascular, paravascular and significance for neurodegenerative diseases. Neurobiol Dis. 2016. ↩︎
Da Mesquita S, et al. Functional aspects of meningeal lymphatics in ageing and Alzheimer's disease. Nature. 2018. ↩︎
Weller RO, et al. Lymphatic drainage of the brain and the pathophysiology of neurological disease. Acta Neuropathol. 2009. ↩︎